/*
 * Created on Jan 26, 2007
 * Created by Paul Gardner
 * Copyright (C) Azureus Software, Inc, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

package org.gudy.azureus2.core3.util;

import java.nio.ByteBuffer;

public class ReferenceCountedDirectByteBuffer extends DirectByteBuffer {
    private DirectByteBuffer basis;

    private int ref_count = 1;

    protected ReferenceCountedDirectByteBuffer(DirectByteBuffer _basis) {
        this(_basis.getBufferInternal());

        basis = _basis;
    }

    protected ReferenceCountedDirectByteBuffer(ByteBuffer _buffer) {
        super(_buffer);
    }

    public ReferenceCountedDirectByteBuffer duplicate(int offset, int length) {
        ByteBuffer duplicate = getBufferInternal().duplicate();

        duplicate.position(duplicate.position() + offset);

        duplicate.limit(duplicate.position() + length);

        ReferenceCountedDirectByteBuffer res = new ReferenceCountedDirectByteBufferDuplicate(duplicate);

        return (res);
    }

    public void incrementReferenceCount() {
        synchronized (this) {

            ref_count++;

            // System.out.println( "" + this + ": rc=" + ref_count );
        }
    }

    public void decrementReferenceCount() {
        synchronized (this) {

            ref_count--;

            // System.out.println( "" + this + ": rc=" + ref_count );

            if (ref_count == 0) {

                basis.returnToPool();
            }
        }
    }

    public int getReferenceCount() {
        synchronized (this) {

            return (ref_count);
        }
    }

    public void returnToPool() {
        decrementReferenceCount();
    }

    protected class ReferenceCountedDirectByteBufferDuplicate extends ReferenceCountedDirectByteBuffer {
        protected ReferenceCountedDirectByteBufferDuplicate(ByteBuffer owner) {
            super(owner);

            incrementReferenceCount();
        }

        public ReferenceCountedDirectByteBuffer duplicate(int offset, int length) {
            Debug.out("dup dup");

            return (null);
        }

        public void returnToPool() {
            decrementReferenceCount();
        }

        public void incrementReferenceCount() {
            ReferenceCountedDirectByteBuffer.this.incrementReferenceCount();
        }

        public void decrementReferenceCount() {
            ReferenceCountedDirectByteBuffer.this.decrementReferenceCount();
        }
    }
}
